DISSERTATION RESEARCH: Nutrient cycling and distribution over multiple scales in a Kenyan savanna as mediated by an acacia-ant mutualism

论文研究：以金合欢-蚂蚁互利共生为媒介的肯尼亚稀树草原多尺度养分循环和分配

• 批准号: 0807514
• 负责人: Peter Vitousek
• 金额: $ 1.2万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0807514&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Nutrient; cycling; distribution

In Kenya, a common Acacia tree in effect employs an army of ants to defend its leaves from being eaten by giraffes, elephants, and other large herbivores. In exchange for this protection, the trees provide the ants with nesting space and nectar for food. This mutually beneficial interaction between Acacia trees and ants may involve more than just protection, though: preliminary data suggest that at least some of the ants may also fertilize the trees in which they live. The objective of this research is to examine how nutrients are exchanged between ants and trees, to determine how this interaction might affect soil nutrient availability, and to investigate the effect of the disappearance of large mammals on these processes. To address these questions, this study will combine a nitrogen-tracing experiment with soil sampling to track ant-derived nutrients, in addition to using long-term mammal-exclusion plots to investigate the influence of mammals.This study incorporates work directly applicable to land management in eastern Africa: loss of native browsers, a significant problem across much of Africa, could alter the mutually beneficial interaction between ants and plants, in turn affecting soil fertility and forage quantity and quality. This research will employ a Kenyan research assistant as well as involve undergraduates from Stanford University. Results of applied aspects of the research will be communicated to local land owners and managers through local publications, talks, and conversations.

在肯尼亚，一棵普通的相思树实际上雇佣了一群蚂蚁来保护它的叶子不被长颈鹿、大象和其他大型食草动物吃掉。作为对这种保护的交换，树木为蚂蚁提供了筑巢的空间和花蜜作为食物。不过，金合欢树和蚂蚁之间的这种互利互动可能不仅仅是保护：初步数据表明，至少有一些蚂蚁还可能为它们所居住的树木施肥。本研究的目的是研究蚂蚁和树木之间如何交换养分，以确定这种相互作用如何影响土壤养分的有效性，并调查大型哺乳动物的消失对这些过程的影响。为了解决这些问题，本研究将联合收割机与土壤采样相结合，以追踪蚂蚁来源的营养物质，此外还将使用长期禁止哺乳动物的地块来调查哺乳动物的影响。土著浏览者的消失，是非洲大部分地区的一个重要问题，可能会改变蚂蚁和植物之间的互利互动，进而影响土壤肥力和牧草的数量和质量。这项研究将雇用一名肯尼亚研究助理，并涉及斯坦福大学的本科生。研究的应用方面的结果将通过当地出版物，讲座和对话传达给当地土地所有者和管理者。